I saw a great thread about replacing a one-piece tub/shower surround.
You don't - you get the three piece tub/shower surround and caulk it
together. A one piece is generally for new construction where you can
get through the walls.

But, here's my question: Our bathroom is about 58" wide. The tub sits
opposite the door, taking up the back wall. It's a one-piece surround.
We want to replace it with a tub and tile. But...how do you fit a tub
fixture that's 58" wide, into a 58" space? From corner to corner it's
wider than 58", and it's not just a plank - the depth of the tub makes
it so you can't just shove it in.

So how do you get it in? It seems to be that you'd need to take out the
wall to get some wiggle room. And hope there aren't tricky beams in the
way. I'd appreciate any thoughts on the matter.

Chris